<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>季节判断</title>
</head>

<body>
    <script>
        var a = prompt("请输入月份：")
        if (a >= 3 && a <= 5) {
            alert("当前季节为春季！")
        } else if (a >= 6 && a <= 8) {
            alert("当前季节为夏季！")
        } else if (a >= 9 && a <= 11) {
            alert("当前季节为秋季！")
        } else if (a == 12 || a <= 2) {
            alert("当前季节为冬季！")
        }
    </script>
</body>

</html>